The present invention relates to iron type golf club heads and in particular to a cavity back iron type golf club head with a single back bar weight mass configuration, or a set of such iron type golf club heads.
The majority of peripheral weighted iron type golf club heads are formed with a rear cavity and a peripheral mass distributed around the outer rear edge of the club head at at least the heel, toe and sole portions to more evenly distribute the mass for the purpose of providing a more efficient energy transfer of force to a golf ball being struck off of the center of percussion. These type of club heads represent a significant advance in the state of the art. Other advances in weight distribution have been developed as evidenced by my own U.S. Pat. No. 4,826,172, the patent to Winquist 3,814,437, the patent to Johnstone 3,059,926, the patent to Lamina 4,715,601, and the patent to Cosby 3,858,886 among others. These patents generally stand for the proposition that a mere distribution of weight around the outer periphery does not impart maximum transfer of force to a golf ball struck in and around the center of percussion. The aforementioned patents represent various golf club head structures which made up the state of the weight distribution art in golf club heads.
The present invention uses a selective placement of a single back bar weight mass offset from the center of percussion within the cavity on the rear face of the club head to effectively alter the performance of each club. The invention preferably includes a set of iron type golf club heads having such a single back bar weight, with the position of the back bar weight being varied to provide the most optimum effect for each club head. For example, the single back bar weight may be gradually moved forward from proximate the center of gravity toward the toe portion for middle to long irons (low lofted irons). Conversely, the single back bar weight may be moved back from proximate the center of gravity to the heel portion for the shorter (higher lofted) irons. In each case, the respective club heads will produce a better feeling club which enhances the golfer's ability to obtain more meaningful distance and accuracy for all the irons in a set. The shape of the back-bar weight can be varied to maximize the performance of the club for particular situations or golf swings. The unique weight placement and design of the single back bar weight permits a golfer to obtain the best results from his swing and style and execute various golf swing techniques such as drawing or fading a golf ball, when desired. The various shapes, sizes and locations of the single back bar weights within the back cavity may be altered to produce a set of high performance golf club heads which meet the specific needs of a golfer and thus correct problems encountered in the golf swing of the golfer.
The present invention contemplates a variety of single bar back weight placements as well as a variety of shapes and sizes. In a preferred embodiment, a single bar back weight extends from the peripheral mass adjacent the sole to the peripheral mass adjacent the top ridge within the back cavity. The addition and unique location of the single back bar to a club head significantly alters the center of gravity of an iron type golf club head. The various embodiments contemplated by the present invention permit moving the center of gravity upward toward the top ridge, downward toward the sole, forward toward the toe and backward toward the heel. It is contemplated that the preferred embodiment of the single back bar weight mass may be generally rectangular in shape and either a vertical or sloped configuration. In alternative embodiments, the single back bar may be curved, angled or formed of a variety of geometric shapes. The single back bar weight may be of various widths and sizes and may also incorporate an integral tertiary mass to more precisely concentrate the mass of the club and/or define the exact location of the center of gravity in a particular golf club head.
Among the objects of the present invention are an improved iron type golf club head design or set of iron type golf club heads which maximize energy transferred through a golf ball being struck while maintaining improved control, feel, accuracy and distance. Another object is to provide a golf club head which minimizes variances in a golf ball's flight if the ball is hit off center. Still another object of the invention is to provide an improved set of conventional perimeter weighted golf club heads wherein the center of gravity of the heads may be precisely located from a position toward the toe for the longer irons to a position toward the heel for the shorter irons. Yet another object is to provide iron type golf club heads, and sets of such golf club heads, that are designed to correct particular shortcomings of certain golfers, such as the tendency to hit the ball with the club head open, closed, fat or thin.
These and other objects will become apparent with reference to the following specification and drawings.